Epidemic spread of malaria – home sweet home?
Diagnosis of Malaria parasites has got high relevance in many parts of the world.
The significant numbers of malaria infections and high death rates throughout the years make malaria the most dangerous parasitic infection worldwide.
For example, these global referring numbers are given by the WHO in its world malaria report 2019 :
in 2018 there were 228 million malaria cases.
compared to that:
in 2010 there were 251 million malaria cases.
In the same years death rates were remarkable:
in 2018 there were 405,000 deaths from malaria.
in 2010 there were 585,000 deaths from malaria.
We can remark a reduction, even if small, which is thanks to vector control strategies and chemoprophylaxis .
However, numbers remain high and therefore, diagnostic methods to detect the malaria causing parasite Plasmodium, are an important part of case management.
Early diagnosis of malaria infections saves lives and prevents whole populations from suffering severe organ failures  and an epidemic spread, caused by the bites of infected female Anopheles mosquitos  which are endemic in tropical and subtropical regions. This affects South-East Asia, Eastern Mediterranean, Western Pacific, South and Central America, but mostly sub-Saharan Africa .
There are numerous problems that make reliable diagnosis, thus, the fight against malaria in endemic regions difficult.
First of all, an infected person can remain undetected for several weeks.
This is on the one hand due to long incubation periods of Plasmodium species, which is at least 8 to 15 days for the most harmful species P. falciparum. It is responsible for 80% of human infections and for the highest death rate of malaria infections.
On the other hand, it is because at the early stage of infection, symptoms are uncharacteristic and can mislead to wrong interpretations.
Secondly, most affected regions tend to have limited capacity of technicians and reagents for a proper and efficient diagnosis, a low level of training or a poor quality assurance program.
At the same time, these regions are dealing with large numbers of cases continuously, which causes high workloads.
Thirdly, a proper diagnostic method has to fulfil some important criteria:
it has to provide information on the species, of which there are 4 human pathogens.
The method should give information on the quantity of parasites and has to make possible the detection of a low number of parasites.
Ideally, it can provide information on the life cycle stages of the parasite.
Most important, results have to be reliable, both for negative and for positive results.
So far, the criteria for diagnosis.
To make the methods practicable in endemic regions, the local problems have to be compensated by further features like:
performing should be easy with little training required, reagents should be cheap, and the method should allow examination of many cases at a time.
 Word Health Organization: “Malaria – key facts”
 World Malaria Report 2018; World Health Organization (GLOBAL AND REGIONAL MALARIA BURDEN, IN NUMBERS – p.12 Malaria Cases; p13 Malaria Deaths) https://apps.who.int/iris/bitstream/handle/10665/275867/9789241565653-eng.pdf?ua=1
 World Health Organization – This year’s report at a glance
 Robert Koch Institut
Part 2: Let’s take a look at some different kinds of diagnostic methods and their qualities.